The present disclosure relates generally to welding systems, and, more particularly, to starting an arc of certain processes used in the welding systems.
Some welding systems use arc welding processes, such as gas tungsten arc welding (GTAW), also known as tungsten inert gas (TIG) welding, where a non-consumable tungsten electrode is used to produce a weld. Welding systems that use the TIG welding process may start an arc in several ways, including directly or remotely. Directly starting the arc may be referred to as a “scratch start.” To scratch start the arc, the tungsten electrode is scratched against the work with the power on to strike the arc. However, contamination of the weld and the electrode may occur using scratch starting. Remotely starting the arc may be referred to as a “high frequency (HF) start.” While no contact between the tungsten electrode and work is made, HF starting the arc may require a relatively high voltage high frequency sinusoidal waveform (a few MHz) to be applied to the tungsten electrode. The high frequency electric field generated at the tip of the electrode breaks down the dielectric resistance of the path between the electrode tip and the work piece within the column of shielding gas so as to form a conductive path in the shielding gas so that the arc can be established. Unfortunately, due to the large output voltage that facilitates the start, HF waveform arc starts typically create a relatively large electromagnetic interference (EMI) footprint, which may cause problems for nearby electronics, among other things.